Current Research

Opportunities are available at UF and partnership institutions for students to learn about and to undertake projects in different aspects of paleontology, geochronology, sedimentary geology and tectonics. A list of current peer-reviewed journal articles can be accessed here. Short synopses of recent abstracts appear below.

Thirty leaf morphotypes are described from the Dawson Clay Pit locality of the Claiborne Formation in Tennessee and their leaf architecture is examined to determine paleoclimate. Despite only sharing two morphotypes with the nearby Powers Clay Pit, paleoclimate estimates for the two are nearly identical. The two localities likely had a seasonal subtropical climate.

ANTECEDENTS OF THE MODERN TROPICAL AMERICAN CONE SNAIL FAUNA: PHYLOGENETIC DIVERSITY AND BIOGEOGRAPHICAL HISTORY OF LATE MIOCENE TO PLIO-PLEISTOCENE CONIDAE IN THE CONTEXT OF MAJOR REGIONAL ENVIRONMENTAL CHANGE

Jonathan Hendricks, San José State University, USA

Advances in molecular phylogenetics have allowed for the resolution of several relationships among extant cone snail species and have provided information as to which shell patterns are present in particular clades. This allows for the incorporation of fossil species, whose patterns are revealed by UV light, into the phylogenetic framework of this group. Here, the biogeography of and the relationships among Neogene tropical cone snails are examined.

FOSSIL LIANAS FROM THE MIOCENE OF PANAMA AND THEIR PALEOENVIRONMENTAL IMPLICATIONS

We have identified several fossil lianas from the Cucaracha Formation of Panama. Annual growth rings of co-occuring fossil woods suggest a short dry season, and oxygen isotopes in mammal teeth do not support a seasonal forest environment. We conclude that the presence of these lianas suggest natural disturbance in a tropical forest with a short dry season.

TECTONIC EVOLUTION OF THE ISTHMUS OF PANAMA: THERMOCHRONOLOGIC EVIDENCE FOR A LATE MIOCENE ISTHMUS UPLIFT FROM CENOZOIC SEDIMENTS, SOUTHWESTERN PANAMA

Michael Kedenburg, University of Florida, USA

Gephen Sadove, University of Florida, USA

Diego Ramírez, University of Florida, USA

David Foster, University of Florida, USA

Camilo Montes, Universidad de Los Andes, Colombia

Thermochronological analysis of Cenozoic sediments from southwestern Panama suggest late-stage cooling associated with the closure of the Isthmus between 9 Ma and 2 Ma. Apatite U-Th/He ages from the Tonosi Formation and the Covachon Formation suggest that the Tonosi Peninsula was above sea level between 9 and <2 Ma.

EXCEPTIONAL THREE-DIMENSIONAL PRESERVATION OF MUSCLES IN A FOSSIL GHOST SHRIMP

Propodi of a Pleistocene-Holocene ghost shrimp (Sergio sp.) with beautiful three-dimensional muscle preservation have been found ex-situ at the Pacific entrance of the Panama Canal. The muscle structure is similar to that of extant ghost shrimp.

Hundreds of carapaces of the crab Paleopinnixa sp. have been found in the lower Miocene Culebra Formation of Panama, providing the opportunity to do a population study. Females are, on average, slightly wider than males and have greater maximum abdominal width than males. As far as ontogenetic characteristics, the ratio of frontal orbital width to total width decreases with growth.

EXPLORING THE NEODYMIUM ISOTOPIC SIGNATURES OF MARINE SEDIMENTS FROM OUTCROPS ACROSS PANAMA: A CASE STUDY TO BETTER UNDERSTAND SHOALING OF THE CENTRAL AMERICAN SEAWAY

When fish teeth and other debris sink to the bottom of the ocean, it is possible for them to take up the Nd-isotopic composition of the waters they fall into. This neodymium can be measured as a water mass tracer for paleocirculation. In this study, marine sediments collected from the Azuero Peninsula of Panama were examined for comparison with other marine sediments from other exposures in Panama.

SVP | Society of Vertebrate Paleontology (2015)

A PRELIMINARY REPORT ON THE TURTLES FROM THE LATE MIOCENE OF CENTRAL PANAMA

Fossil turtles have been found in the late Miocene Chagres, Alhajuela, and Gatun Formations of Panama. The non-marine turtles of these assemblages from Panama have North American and Old World affinities, suggesting that there was still a biogeographic barrier to dispersal from South America during the late Miocene.

NEW FOSSILS OF THE RARE EARLY MIOCENE FLORIDATRAGULINE CAMEL FLORIDATRAGULUS NANUS FROM FLORIDA AND CENTRAL AMERICA

Fossils of floridatraguline camels have been found from the early Miocene of Panama and have tentatively been assigned to the species Floridatragulus nanus. Previously only known from a single m3 from the Hemingfordian Garvin Gully locality of Texas, F. nanus has also been found in the Hemingfordian Thomas Farm locality of Florida.

FIRST RECORD OF PROCYONIDS FROM THE THOMAS FARM FOSSIL LOCALITY, GILCHRIST COUNTY, FLORIDA

Screenwashing at the early Hemingfordian Thomas Farm site in Florida has produced isolated carnivoran teeth, some of which have been identified as those of procyonids. The specimens have been assigned tentatively to Bassariscus.

In North America during the Miocene-Pliocene, the latitudinal temperature gradient strengthened and affected the distribution of biomes until they settled at their modern-day latitudes. Through cluster analysis incorporating faunal data from across North America, we found that faunal provinces had greater latitudinal dissimilarity during the Hemphillian than in the Hemingfordian and that beta diversity had increased from the Hemingfordian to the Hemphillian.

Scientists from the University of Florida have teamed up with high school teachers to create three lessons that use equid evolution to teach high school students evolution, intraspecific variability, and climate change. The lessons include taking several measurements of casts and 3D prints of horse teeth, comparisons of several horse species from one locality, and the creation of an exhibit illustrating the complex phylogeny of horses.

Over 70 specimens from 4 rodent families (Sciuridae, Jimomyidae, Heteromyidae, and Cricetidae) have been found in Panama and represent the only Miocene rodents known from Central America. A notable feature of these early Miocene is the abundance and diversity of jimomyids, an extinct family of rodents.

NEW EARLY MIOCENE CAMELIDS (ARTIODACTYLA, FLORIDATRAGULINAE) FROM PANAMA AND THE RELATIONSHIP OF FLORIDATRAGULINES TO CAMELINAE

Fossils of the floridatraguline camels Aguascalientias and Floridatragulus nanus from the early Miocene of Panama exhibit features that suggest that Floridatragulinae may be paraphyletic with respect to Camelinae.

THE NEW WORLD TROPICS AS A CRADLE OF MAMMALIAN BIODIVERSITY: A PRE-GABI RECORD

Confounding factors during the Great American Biotic Interchange (GABI) have previously made it difficult to distinguish the source of New World Tropics (NWT) biodiversity. However, fossils from the pre-GABI, He1 Centenario fauna have allowed us to test our hypotheses regarding NWT biodiversity. We have found that there are significantly more first appearances in the tropics than outside the tropics and that our data do not support the "Out of the Tropics" model.

Botany 2015 | Botanical Society of America (2015)

LIANAS FROM THE MIOCENE OF PANAMA: ANATOMY AND IMPLICATIONS FOR PALEOENVIRONMENT

Lianas are an important part of tropical and subtropical forests, however few of the entries in the "Fossil Record of Climbers" database are wood/stems. We developed a protocol for identifying fossil lianas by their wood and used it to identify fossil liana stems from the Lower Miocene Cucaracha Formation of Panama. An abundance of lianas can signal seasonality or disturbance, and we conclude that the abundance of lianas in the Cucaracha Formation is due to disturbance, not seasonality.

Our teacher-scientist partnership, mediated by an education and training institute, is focused on spreading knowledge of scientific research to K-12 and the wider society. After designing and implementing a high school biology course on horse evolution, we discuss what we have learned from our partnership and how we might include more K-12 teachers.

Using 3D technology, we have developed a transferable product where teachers and scientists have worked together to create lessons using 3D printed teeth of the extinct giant shark Carcharocles megalodon. By studying these 3D models and using the national digitization portal iDigBio, our activity allows for STEM integration and a greater understanding of evolution and extinction for K-12.

INTERNATIONAL RESEARCH EXPERIENCES: FOSSILS AND PALEONTOLOGY IN PANAMA

We have developed an annual teacher-scientist partnership program that has teachers become familiar with paleontological field research in Panama. Products of this partnership include meeting presentations, publications, and lesson plans aligned with new learning standards. As a result of this program, there has been greater appreciation for teacher-scientist partnerships and increased knowledge in paleontology and related fields such as biology and geology.

NNB4 | Network for Neotropical Biogeography (2015)

POPULATION STUDY OF PALAEOPINNIXA SP. (DECAPODA: HEXAPODIDAE) FROM THE CULEBRA FORMATION OF THE EARLY MIOCENE PANAMA CANAL BASIN

Most fossil decapod faunas produce only a few dozen individuals of a given species, however the hundreds of specimens of Palaeopinnixa sp. found in the Culebra Formation is an exception. The large number of individuals allow for a population study of intraspecific variation, sexual dimorphism, and possible ontogenetic changes within Palaeopinnixa.

PEBAS, ACRE, AND PARANA SYSTEMS: CONNECTING THE DOTS TO ELUCIDATE MAMMALIAN BIOGEOGRAPHIC PATTERNS IN THE MIOCENE OF SOUTH AMERICA

The difference in Tertiary mammal assemblages of northern and southern South America can sometimes by latitudinal differences. Faunal analysis of seven Miocene faunas of South America tested the effect of time and latitude on mammal distribution and produced unexpected results. The vicariant barrier effects of the Pebas megawetland and the fluvial Acre system are here proposed as an explanation for these results.

Many of the mammalian taxa from the Miocene of Panama have Eurasian affinities and include a occurance of platyrrhine monkeys, otherwise only known from South America. This biogeographic pattern is also evident in other mammalian clades and in several groups of reptiles, supporting an earlier stage of biotic interchange before the onset of the GABI that is consistent with recent reconstructions of a narrow Central American Seaway during the early Neogene.

FOSSIL INVERTEBRATES AND SR-ISOTOPE AGE ESTIMATE FOR THE ALAJUELA FORMATION, CENTRAL PANAMA

A 36 m stratigraphic section from the upper Alajuela Formation contains terrestrial and marine vertebrates and near-shore to shallow marine invertebrates. 87Sr/86Sr geochronology was used to determine the age, which was found to be late Miocene (~9.8 Ma) instead of early Miocene in age. The marine fossils and strontium ratios suggest that the Alajuela Formation overlaps in time with the late Miocene Gatun Formation, and that the Alajuela Formation represents a shallow marine setting that may have been closer to the coastline than the Gatun Formation.

Fossil vertebrates were collected in 1959 from the shores of Lake Alajuela (then Lake Madden). The approximate sites where these fossils were found were relocated in 2014, and additional terrestrial and marine fossils were collected. The age of the Alajuela Formation will likely be revised as late Miocene, which will make the Alajuela faunule the first late Miocene terrestrial fauna from Panama.

Some have claimed that the Hodge's Hill Microsite locality in Panama represents a crocodylian hatchery due to the abundance of small crocodylian teeth. Measurements of crown height and body length of modern yearlings were compared to measurements of fossil crocodylian teeth from several localities. Although Hodge's Hill had smaller teeth than other sites, they were still larger than modern yearlings, suggesting that the locality may represent a safe haven for sub-adult crocodylians.

OLIGOCENE AND MIOCENE BATS (MAMMALIA: CHIROPTERA) FROM FLORIDA AND PANAMA, AND THE ORIGINS OF THE NEOTROPICAL CHIROPTERAN FAUNA

Bat fossils from Florida and Panama have added a significant amount to our knowledge of the origins of the Neotropical chiropteran fauna. Previously, several New World bat families were believed to have arisen in South America and immigrated to North America during the Great American Biotic Interchange. However, Oligocene and Miocene bats with Neotropical affinities found in Florida and Panama suggest that some New World bat families may have first appeared in North America.

SHARKS (CHONDRICHTHYES) OF THE CHUCUNAQUE FORMATION OF LAKE BAYANO AND THE BIOGEOGRAPHIC IMPLICATIONS

Shark fossils from nine localities in Lake Bayano are dominated by shallow, nearshore taxa, similar to the contemporaneous, shallow-water Gatun Formation. However, teeth of deep-water sharks were also found in Lake Bayano. This difference may be due to the Gatun Formation's location between the Caribbean Sea and the Pacific Ocean and Lake Bayano's orientation to the Pacific Ocean. Biogeographic analysis of the sharks' affinities will be established and compared to other Neotropical assemblages.

PALEOBIOGEOGRAPHIC IMPLICATIONS OF PARINARI (CHRYSOBALANACEAE) FOSSILS FROM THE EARLY MIOCENE OF PANAMÁ

The pantropical plant family Chrysobalanaceae is believed to have an Old World origin. New fossil endocarps from the Cucuracha Formation of the Panama Canal area (~19Ma) appear to be aligned with Parinari, a genus with its highest species richness in the Neotropics. Recent phylogenetic studies suggested that the age of crown-group Parinari is 8-17Ma. Depending on the affinities of these new fossils, our understanding of the evolutionary history of Parinari could change drastically.

NEW PALEOGEOGRAPHIC MODEL FOR THE CLOSURE OF THE ISTHMUS OF PANAMA

Camilo Montes, Universidad de los Andes, Colombia

A. Cardona, Universidad Nacional, Colombia

Carlos Jaramillo, Smithsonian Tropical Research Insitute, Panama

F. Moreno, University of Rochester, USA

According to a new model for the closure of the Isthmus of Panama, a land connection between eastern Panama and northern South America was present by ~13-15Ma. Deep water connections between the Caribbean Sea and the Pacific Ocean would no longer have existed at this time. Eastern Panama was connected to North America at least until the early Miocene, however deformation of the Isthmus in the early to middle Miocene caused fracturing and allowed for the formation of a shallow water passage west of the Canal Basin. This passage was then cut off by the formation of the El Valle Volcano.

PROVENANCE ANALYSIS AND THE MIDDLE MIOCENE CLOSURE OF THE CENTRAL AMERICAN SEAWAY

Camilo Montes, Universidad de los Andes, Colombia

A. Cardona, Universidad Nacional, Colombia

Although the closing of the Isthmus of Panama likely had worldwide effects, it is difficult to assess the role of the Isthmus because of the difficulty in establishing the timeline of seaway closure. Detrital zircons were collected for provenance analysis and a strong, uniquely Panamanian signature appears in middle Miocene strata of northwesternmost South America, marking the beginning of fluvial detrital exchange between the Panama arc and South America.

Dimila Mothe, Museu Nacional/Federal University of the Rio de Janeiro State, Brazil

Leonardo S. Avilla, Federal University of the Rio de Janeiro State, Brazil

Phylogenetic and biogeographic analyses are conducted on trilophodont gompthotheres. Vicariant events appear to be related to climatic-enviromental changes, not geological events such as the uplift of the Isthmus of Panama. The greatest amount of diversification in trilophodont gomphotheres likely took place in central North America during the late Miocene.

THE SYSTEMATICS OF THE HIPPIDIFORMES (EQUIDAE: PERRISODACTYLA: MAMMALIA)

Leonardo S. Avilla, Federal University of the Rio de Janeiro State, Brazil

Dimila Mothe, Museu Nacional/Federal University of the Rio de Janeiro State, Brazil

Revision of Hippidiformes reveals that several changes must be made to the taxonomy of this group in order to properly represent valid relationships. Hippidiformes appear to have originated and diversified in the Late Miocene of North America, and one genus dispersed to South America before Hippidiformes went extinct in North America by the middle Pleistocene.There they diversified before becoming extinct in South America at the end of the Pleistocene.

LINKS BETWEEN TECTONICS, CLIMATE, AND EVOLUTION THROUGHOUT THE CENOZOIC

Pierre Sepulchre, LSCE/CNRS, France

Tools such as General Circulation Models have been used to quantify the impact of the uplift of the Andes and the closure of the Central American Seaway on global and regional climate. Continental effects of the Andes uplift can also be modeled and it appears that mechanical and hydrological effects of the uplift do not act in the same direction. These models do not precisely explain environmental change through time on a regional scale. Possible new techniques for regional scale paleoclimate modeling will be discussed.

Representatives of GABI RET presented on how their partnership (PCP-PIREteach) has impacted science teachers and their middle and high school students by giving them the opportunity to interact with an international community of scientists and get a glimpse of STEM careers. These teachers explain how they have changed their classroom practices to produce an authentic science curriculum that follows the Next Generation Science Standards’ Science and Engineering Practices.

SVP | Society of Vertebrate Paleontology (2014)

The giant predatory shark Caracharocles megalodon likely played a key role in marine ecosystems. The extinction of this giant shark is not well understood. An analysis of the body size of several specimens shows that the size of C. megalodon was stable over time, and body size changes were not an important factor in its extinction. The estimated extinction time of C. megalodon is the Pliocene-Pleistocene boundary, about 2.5 Ma, which coincides in the extinction of smaller prey and the evolution of new competitors.

ISOTOPE ECOLOGY OF A NEW MAMMALIAN FAUNA FROM THE LATE MIDDLE MIOCENE OF TROPICAL SOUTH AMERICA (PERUVIAN AMAZONIA)

Julia Tejada-Lara, University of Florida, USA

Bruce MacFadden, University of Florida, USA

Rodolfo Salas-Gismondi, Université Montpellier, France

Patrice Baby, Université de Toulouse, France

Pierre-Olivier Antoine, Université Montpellier, France

Although the Miocene was surely an important time in the evolutionary history of many animals and plants in the Amazonian region, there is little vertebrate fossil evidence from the area. Faunal analysis of the newly described Fitzcarrald fauna from the late Miocene of western Amazonia in Peru and isotopic analysis offers new insight into the devlopment of proto-Amazonia.

Dental microwear texture analysis is conducted on extinct xenarthrans. Examination of microwear in extant xenarthrans has provided useful information on the relationship between dentin microwear and diet. No significant difference in dental microwear is detected within a genus during glacial and interglacial periods in the Pleistocene. Diet of the extinct xenarthrans based on dental microwear attributes is also discussed.

PALEOBIOGEOGRAPHY OF NON-EQUID PERISSODACTYLS FROM THE EARLY MIOCENE OF PANAMA

The discovery of chalicotheriid and rhinocerotid fossils in the Panama Canal Basin may shed light on the timing of dispersal events into North America. The primitive morphology of the chalicotheriid along with its age (after the first dispersal of chalicotheriids into North America) suggests that chalicotheriids emigrated multiple times from Eurasia. The co-occurance of Aphelops and Floridaceras in the Centenario Fauna suggests that the two genera immigrated to North America in the same dispersal event.

A NEW EARLY MIOCENE PARAHIPPINE (MAMMALIA, EQUIDAE) FROM THE PANAMA CANAL AREA, CENTRAL AMERICA

Parahippine fossils from the late Arikareean Las Cascadas assemblage are described. Two innovations appeared in tridactyl parahippines: the inception of hypsodonty and the tooth crowns coated in cementum. The Panamanian parahippine possesses incipient hypsodont dentition but lacks cementum. The absence of mesodont parahippines like this one in the younger Centenario Fauna of Panama suggests that these horses did not persist the New World Tropics as they did in higher latitudes.

The discovery of seven isolated teeth of a new platyrrhine monkey from the early Miocene of Panama marks the first known evidence of anthropoid monkeys in Central America prior to the rise of the Isthmus of Panama and the Great American Biotic Interchange.

AGE OF THE TARIJA FAUNA, BOLIVIA: IMPLICATIONS FOR EQUUS DISPERSAL AND CALIBRATION OF GABI 3

The Tarija fauna of southern Bolivia records the height of the Great American Biotic Interchange. Previously, horses (genus Equus) were believed to have arrived in South America as part of GABI 4, which defines the base of the Lujanian SALMA. However the horses found throughout the Tarija sequence suggest that the genus arrived in South America earlier, in GABI 3.

OPTICS AND PHYLOGENY: A GLIMPSE INTO THE PAST THROUGH COMPOUND EYES

Javier Luque, University of Alberta, Canada and Smithsonian Tropical Research Institute, Panama

A. Rich Palmer, University of Alberta, Canada

Eyes have evolved independently many times in higher taxa and can serve as useful tools in resolving evolutionary relationships. One group that can benefit from an analysis of eye evolution is crustaceans, which have several different optical designs. A study of the eyes of the group Podotremata suggests that the group might be paraphyletic, with Podotremata representing not a monophyletic group but a grade of increasing morphological complexity.

A NEW PYGMY SPERM WHALE (ODONTOCETI, PHYSETEROIDEA, KOGIIDAE) FROM THE LATE MIOCENE OF PANAMA

A pygmy sperm whale from the late Miocene Piña Facies of the Chagres Formation of Panama is the first record of a kogiid in the Northern Neotropics. A phylogenetic analysis including this new whale produced a strict consensus tree that placed it in a crown group of kogiid whales that included several extinct Neogene species and the extant Kogia spp.

CHONDRICHTHYAN FAUNA FROM THE LATE MIOCENE CHAGRES FORMATION (PANAMA CANAL BASIN): A NEW PALEOENVIRONMENT INFERENCE

Two chondricthyan assemblages are reported from the Rio Indio and Piña Facies of the late Miocene Chagres Formation. Paleobathymetry analyses of the assemblages from the two facies show that the taxa from the Rio Indio Facies have a neritic depth preference while those from the Piña Facies have deeper, oceanic affinities.

In order to facilitate communication between the scientists of PCP PIRE and the general public, different types of media are used to provide a diversity of content. The project website and eNewsletter present the bulk of the information and updates on the project while the blog, Facebook, Twitter, and Flickr provide short-form content, updates, and photos to the public. Tracking what is trending on these websites using Google Analytics and built-in statistics platforms allow us to understand what content the public is most receptive to.

GEOLOGICAL RECONNAISSANCE OF THE MIDDLE-LATE MIOCENE ALHAJUELA FORMATION (PANAMA): IMPLICATIONS FOR SHOALING OF THE CENTRAL AMERICAN SEAWAY

Stratigraphic data from the Alhajuela Formation provides new information related to the shoaling and closure of the Central American Seaway. The transgressive sequence observed in the Alhajuela Formation is consistent with paleobathymetry data from the late Miocene Gatun Formation, which is contemporaneous to the Alhajuela Formation or slightly younger.

AN UNDERGRADUATE FIELD COURSE IN THE AZUERO PENINSULA, PANAMA: INTERNATIONAL COLLABORATION BETWEEN RESEARCH INSTITUTIONS IN COLOMBIA, PANAMA, AND THE USA

Undergraduate PCP PIRE interns collaborated with students from the Universidad de Los Andes to produce original research in several sub-divisions of geology. Interaction between these students necessitated constant communication regardless of previous language experience and skill level. The common interests of the participants and their collaboration in the field allowed them to build valuable work relationships despite any language or cultural barriers.

Botany Conference (2013)

INSIGHTS INTO THE MIDDLE MIOCENE CLIMATIC OPTIMUM FROM A NEOTROPICAL LEAF ASSEMBLAGE

An overview and update on the Fossils of Panama project, an ambitious effort to fully catalog and photograph the fossils of Panama curated at the Florida Museum of Natural History.Full abstract | Fossils of Panama

THE GATUN FORMATION: A NATURAL LABORATORY FOR ANALYSIS OF NEOTROPICAL PALEOECOLOGIC AND DIVERSITY PATTERNS

Eocene marine sediments from Panama preserved a fossil leaflet that was proved to be the first, unequivocal fossil record of the modern cycad genus Zamia based on its characteristic epidermal traits. We adopted morphometric measurements to compare cuticle morphology of the fossil with modern species of Zamia belonging to various clades of the genus. Our results corroborated a closer similarity with Caribbean Zamia species than with other Mesoamerican or South American species.

FOSSIL PYGMY SPERM WHALES (ODONTOCETI; PHYSETEROIDEA; KOGIIDAE) FROM THE LATE MIOCENE OF PANAMA AND EARLY PLIOCENE OF FLORIDA

We describe a new fossil species of pygmy sperm whale from Panama which shows that these cetaceans have been present in the Neotropics during the last 6 million years. We also describe fossil from Florida which show that at least two species of pygmy sperm whales lived in the region about 5 million years ago and formed part of one of the most diverse marine mammal assemblages of that time.

I am investigating well-preserved fruit and seed floras ranging from ~60 to ~19 million years ago, from the Paleocene (Cerrejón & Bogotá floras), Eocene (Tonosí flora), and Miocene (Cucaracha flora) of Central and northern South America (specifically Colombia and Panama), to address the following questions: 1) Was northern South America phytogeographically isolated during the Paleogene? 2) What families first colonized the emergent land in the Panamanian arch during the late Eocene? 3) Did the Panamanian seaway act as a strong geographic barrier between the South and Central American forests in the Miocene?

RECONSTRUCTING THE EXTINCTION OF THE GIANT MEGALODON SHARK (CARCHARCOLES MEGALODON)

Exploring the details surrounding the extinction of the shark C. megalodon, the largest known marine predator, can hopefully offer some insight into current conservation efforts of threatened modern sharks.

BODY SIZE CHANGE OF CARCHAROCLES MEGALODON THROUGH TIME IN COMPARISON WITH CONTEMPORANEOUS MARINE MEGA-FAUNA

Meghan A Balk, University of New Mexico, USA

Catalina Pimiento, University of Sheffield, UK

Body size is inherently related to a species' ecology. Understanding how body size changes in a species and throughout a community through time can reveal changes in a species ecology and relationships within a community. We, Catalina Pimiento and I, are investigating how C. megalodon's body size evolved through space and time, as well as how the body size of species in the marine community changed in the Early Pliocene, at the time of C. megalodon's extinction.

Mapping intraspecific variation of the commonly preserved bivalve Anadara dariensis can allow us to establish a baseline of diversity and changes that are independent of anthropogenic, or human, influence.

Turtle diversity was relatively low in the Panama Canal Basin during the earliest Miocene Las Cascadas Formation (21 million years ago), but greatly increased during the Cucaracha Formation (~19 million years ago) when species diversity more than doubled.

AN EARLY MIOCENE BAT (CHIROPTERA: PHYLLOSTOMIDAE) FROM PANAMA AND MID CENOZOIC CHIROPTERAN DISPERSALS BETWEEN THE AMERICAS

Preliminary high-resolution analysis of teeth measurements of the giant shark Carcharcoles megalodon show an increase in the proportion of larger individuals over time, which may allow broader understanding of the evolutionary advantages and perils of large size.

NEW EARLY MIOCENE BASAL PROCYONIDS FROM PANAMA: THE OLDEST NORTH AMERICAN PROCYONID AND ORIGIN OF THE TRIBE POTOSINI (CARNIVORA, PROCYONIDAE).

A new species of procyonid, a group that includes both kinkajous and raccoons, has been found in Panama, which indicates they evolved and diversified in primarily a tropical and subtropical forest habitat.

PARTIAL SKELETON OF A TOOTHED WHALE (ODONTOCETI, CETACEA) FROM THE MID TO LATE MIOCENE GATUN FORMATION, PANAMA

A new species of toothed whale found in the Gatun Formation, Panama, exhibits a relatively long neck and dense ribs, which are features not typically seen in whales. These features indicate that the Gatun whale likely foraged at shallow depths, an interpretation that is consistent with a depth estimate of 25 meters for the layers in which it was discovered.

DIFFERENCES IN INFERRED FORAGING BEHAVIOR AMONG EARLY MIOCENE SPECIES OF DIPLOTHERIUM: EVIDENCE FROM A NEW FOSSIL DUGONG FROM THE PANAMA CANAL

A well-preserved skull of a new species of fossil dugong was discovered along the Panama Canal from the Culebra Formation. Characteristics of the back of the skull indicate a specialized feeding strategy that differs from closely related dugongs found along the Pacific and Atlantic coasts of North and South America in the fossil record. These results are important for understanding competition among fossil dugong species for dietary resources, like sea grass.

International Bat Research Conference (2013)

A NEW EARLY MIOCENE PHYLLOSTOMINE FROM PANAMA: EVIDENCE FOR A MID CENOZOIC INTERCHANGE OF BATS BETWEEN THE AMERICAS